The Colonial Office established an advisory council in November 1945 to work with the BMA on the reconstruction of Singapore. Among the seventeen members appointed to the council was Wu Tian Wang, a former guerrilla leader and chairman of the communist Singapore City Committee. The MCP enjoyed great popularity in the early postwar days because of its association with the resistance and the Malayan People's Anti-Japanese Army, which also included many noncommunists. In January 1946, the anti-January army was formally disbanded following a final parade at which Mountbatten presented medals to the guerrilla commander, Chin Peng, and the other resistance leaders. All arms and ammunition, which the guerrillas had received in airdrops from the British during the war or captured from the Japanese, were supposed to be surrendered at that time. The CPM, however, secretly retained large stocks of its weapons.

The British legally recognized the MCP in late 1945, largely because of its resistance efforts and its popularity. The party by that time commanded about 70,000 supporters. The MCP at first concentrated its efforts on organizing labor, establishing the General Labour Union, which covered more than sixty trade unions. It organized numerous strikes in 1945 and early 1946, including a two-day general strike in January in which 173,000 workers struck and transport was brought to a halt. In February, after the formation of a Pan-Malayan Federation of Trade Unions claiming 450,000 members in Singapore and the peninsula, the BMA arrested twenty-seven leading communists, banishing ten of them without trial. Thereafter, the MCP adopted a lower profile of quietly backing radical groups that were working for constitutional changes and increasing its control over the labor movement.

In April 1946, the BMA ended with the formation of the Malayan Union, at which time Singapore became a separate crown colony with a civil administration. The two entities continued to share a common currency, institutions of higher learning, and the administration of immigration, civil aviation, posts and telegraphs, and income tax. Opposition to the separation of Malaya and Singapore motivated the formation in December 1945 of Singapore's first indigenous political party, the Malayan Democratic Union (MDU). Although most leaders of the new party were not communist, there were several prominent communists among its founders, including Wu Tian Wang, who saw the Malayan Union as a threat to the vision of a communist, united Malayan republic. The MDU proposed eventual inclusion of Singapore in an independent Malaya within the Commonwealth of Nations. Meanwhile, on the peninsula, conservative Malay leaders, who were concerned about provisions in the Malayan Union scheme that conferred equal political status on immigrant communities, formed the United Malays National Organization (UMNO) in March 1946. After various mass rallies, movements and countermovements, proposals and counterproposals, the British acceded to UMNO wishes. February 1948 marked the formation of the Federation of Malaya, which provided for the gradual assimilation of immigrants into a Malay state working toward independence under British guidance. Singapore remained a separate crown colony.

Elections in Singapore were scheduled for March 1948, at which time a new constitution would go into effect. That document called for an Executive Council of colonial officials and a Legislative Council comprising nine officials and thirteen nonofficials, four nominated by the governor, three chosen by the chambers of commerce, and six elected by adult British subjects who had been resident in Singapore for one year prior to the election. The appointed governor retained power over certain items and veto power over the proceedings of the Legislative Council. The MDU, by then a communist front organization, boycotted the elections and organized mass rallies opposing the new constitution. The moderate Progressive Party was formed in August 1947 by British-educated business and professional men who advocated gradual constitutional reform aimed at eventual self-government. Of the six elected seats on the Legislative Council, three were won by independents and three by Progressives, the only party to contest the elections. In the first municipal election in 1949, the Progressive Party won thirteen of the eighteen seats on the twenty-seven member municipal commission. Voter interest was very low in both elections, however, with only about 10 percent of those eligible registering to vote.

Meanwhile, the MCP had abandoned the moderate stance advocated by its secretary general Lai Teck, who was replaced in March 1947 by Chin Peng. Soon after, it was discovered that Lai Teck had not only disappeared with the party's funds but also been a double agent, serving both the Japanese and the British. Following the establishment of the Federation of Malaya in February 1948, Singapore's communist leaders moved to the peninsula where they reactivated the MPAJA and began fomenting acts of violence and terrorism. This led to the declaration of a State of Emergency in Malaya on June 18 and in Singapore a week later. Although the twelve-year struggle was largely confined to the peninsula, restrictions were placed on meetings and strikes, and the detention of individuals without trial was permitted under the Emergency regulations. The MCP was proscribed by the colonial government in Singapore, and the MDU, fearing the same fate, voluntarily dissolved itself. Left-wing political movements were thus stifled, and the only political party that arose to challenge the Progressives was the Singapore Labour Party formed in 1948. Like the Progressive Party, its positions were moderate and its leadership mostly British educated. Nevertheless, as a result of personal squabbles and factions, the Singapore Labour Party had largely disintegrated by 1952.

The number of elected seats in the Legislative Council was increased to nine in 1951, and the Progressive Party won six of the nine seats in the election that year. The membership of the party never numbered more than about 4,000, the majority of whom were upper or middle class and British educated. The interests of the members of the Legislative Council and the leadership of the Progressive Party were so closely aligned with those of the colonial government that they were out of touch with the masses. Participation in politics was restricted to Straits-born or naturalized British subjects who were literate in English. This exclusion of immigrants and those not educated in English meant that, in the late 1940s, about one-half of Singapore's adult population was disenfranchised.

Although the Chinese-educated took little interest in the affairs of the Legislative Council and the colonial government, they were stirred with pride by the success of the CCP in China. Fearful that support by Singapore's Chinese for the CCP would translate to support for the MCP, the colonial government attempted to curtail contacts between the Singapore Chinese and their homeland. When Tan Kah Kee returned from a trip to China in 1950, the colonial government refused to readmit him, and he lived out his days in his native Fujian Province.

For graduates of Singapore's Chinese high schools, there were no opportunities for higher education in the colony. Many went to universities in China, despite the fact that immigration laws prohibited them from returning to Singapore. To alleviate this problem, wealthy rubber merchant and industrialist Tan Lark Sye proposed formation of a Chinese-language university for the Chinese-educated students of Singapore, Malaya, and all Southeast Asia. Singaporean Chinese, rich and poor, donated funds to found Nanyang University, which was opened in Singapore in 1956.

By the early 1950s, large numbers of young men whose education had been postponed by the Japanese occupation were studying at Chinese-language high schools. These older students were particularly critical of the colonial government's restrictive policies toward Chinese and of its lack of support for Chinese- language schools. The teachers in these schools were poorly paid, the educational standards were low, and graduates of the schools found they could not get jobs in the civil service or gain entrance to Singapore's English-language universities. While critical of the colonial government, the students were becoming increasingly proud of the success of the communist revolution in China, reading with interest the publications and propaganda put out by the new regime.

As the Emergency on the peninsula began to go badly for the communists, the MCP took a renewed interest in Singapore and began organizing protest demonstrations among the disaffected students. Among the brightest and most capable of the older Chinese high school students were Lim Chin Siong and Fong Swee Suan, who both became involved in organizing class boycotts that resulted in a police raid on the Chinese High School in 1952. The two left the school, took low-paying jobs at bus companies, and began working to build communist influence among workers and students. In May 1954, mass student protest demonstrations were organized to oppose a new National Service Ordinance requiring males between the ages of eighteen and twenty to register for part-time national service. Also in May, the Singapore Factory and Shop Workers' Union registered with the government, with Lim as its secretary general; Fong, who was by then general secretary of the Singapore Bus Workers' Union, and C.V. Devan Nair, of (at that time) the Singapore Teachers' Union, were members of the executive board. Dedicated and charismatic, Lim led several well-organized small strikes that were successful in gaining better conditions for the union's workers, and in attracting thousands of recruits for the union. By late 1955, the Singapore Factory and Shop Workers' Union included thirty industrial unions and had a membership of about 30,000.

Data as of December 1989